Optional logging metrics for rule applications

[raghushantha]

Tobias has suggestions around adding useful metrics for rule applications.

Context:

"It would be extremely helpful to have metrics about how often a rule was applied, how often it was violated, and how long evaluation took.
It could be controlled via opt-in so logging is off until you turn it on.
This way, we all could identify the rules violated most often, and initiate educational initiatives, plus find out more about rule quality and relevance.
The best way to consume this info would be through event logs. This would not replace my original suggestion of having a “-Diagnostic” switch. The –Diagnostics switch would apply to the current scenario only and return metrics immediately.
"

[joeyaiello]

Two possible metrics:

• Speed of individual rule invocation
• Frequency of rule failing (i.e. rule is "caught")

And per Tobias' suggestion, rules should be instrumented regardless of whether they fail.